This project aims to study the regulatory and structural steps involved in cell division and differentiation using bacteria as model systems. Cell division will be studied in Escherichia coli using two approaches: (a) Membrane components altered in a cell division mutant will be isolated and characterized. This formation will be used to establish a biochemical assay for in vitro studies of septation. (b) Mutants which map at the terminus of the chromosome will be isolated to study the link between chromosome termination and cell division. These mutants should supply important information on the regulation of cell division. Differentiation will be studied in Myxococcus xanthus. The effect of cAMP on triggering fruiting body formation will be examined on cellular and molecular levels. In addition, the other parameters affecting fruiting will be determined. The genetic transduction system recently developed will be improved to provide a valuable tool for future studies with M. xanthus. The six newly isolated bacteriophages for M. xanthus will be characterized and their effect on different stages of the host's life cycle determined.